Dictionary
Thesaurus
Medical
Scrabble®
Spanish Central
Games
Word of the Day
Video
Blog: Words at Play
My Faves
Medical Dictionary

amino acid

4 ENTRIES FOUND:
  1. amino acid (noun)
  2. alpha-amino acid (noun)
  3. essential amino acid (noun)
  4. nonessential amino acid (noun)

amino acid

noun

Definition of AMINO ACID

:  an amphoteric organic acid containing the amino group NH2; especially :  alpha-amino acid

Learn More About

Ask The Editor Videos

 
Is It 'Attorney Generals' Or 'Attorneys General'?
 
Fun, Funner, Funnest
 
2014 Word of the Year: Behind the Scenes
 
How the Months Got Their Names
 
Webster's Dictionary of 1864
 
Old-School Grammar
 
Schwa
 
That vs. Which
Test Your
Vocabulary!
Word of the Day
February 28, 2015
pontificate Hear it
To speak pompously or dogmatically
Word Games
Take a 3-minute break and test your skills!
Name That Thing
True or False?
Commonly Misspelled Words
Words at Play
What's a "Lady" in the British Aristocracy?
Ignominious Pasquinade
Trend Watch
Apocalyptic
Putin uncovers his prediction for continuing ceasefire in Ukraine ...
Nuance
Backlash against comments made by a State Department spokeswoman ...
Conflate
Brian Williams's confused recollection of an Iraq War experience ...
Comprise
'Comprised of' or 'composed of'? One man has an answer ...
Inclement
News coverage of a blizzard sent a flurry of lookups for this weather term ...
10 Charming Words for Nasty People
Put-downs with flair
Learn More
When "Literally" isn't, well, literal
How to use a word that (literally) drives some people nuts.
Watch Now
Know what this is?
Test your vocab with our fun, fast game
Go Play
Fear of cats?
Ailurophobia, and 9 other unusual fears
Learn More
Join Us
Merriam-Webster
on Facebook
Merriam-Webster
on Twitter
Bookstore: Digital and Print
Merriam-Webster references for Mobile, Kindle, print, and more.
See All
Other Merriam-Webster Dictionaries